Highly pleasing skin appearance is one of the most desired expectations from personal care products from most consumers around the world. In tropical countries where consumers generally have dark skin, there is a desire to have lighter skin appearance. In consumers who live far from the tropical countries e.g. the Caucasian people who generally have lighter skin, there is a problem of freckles and hyper pigmentation when they are exposed to bright sunshine and therefore they desire an even tanned tone of their skin. Most consumers experience blemishes on their skin after exposure to sun, on healing of wounds or after drying up of acne. In all of the above cases, consumers rely on cosmetic solutions to their skin appearance problems.
Smooth, soft and glowing skin with even skin tone and colour is thus desired by all consumers who use personal care compositions for their skin. To provide this benefit, manufacturers from around the world have tried many approaches. One very commonly used approach is to include sunscreens or sunblocks in such cosmetic products. Another approach to controlling the colour, tone and appearance of the skin is the so called skin lightening approach where chemical compounds are added to personal care compositions which alter the formation of melanin in the skin through biochemical transformation in the stratum corneum thereby changing the colour and appearance of the skin. There are many reactions, some in parallel and some occurring in series which finally affect the formation of melanin in the skin. Different compounds work through different mechanisms. The present inventors have realized over the course of several years of research in this area that there are both advantages and disadvantages of chemical compounds derived from natural source and from those of synthetic origin. The present inventors have judiciously combined one active from each of the natural and synthetic sources in order to get synergistic benefits while minimizing the disadvantage of each type and have thus come up with the present invention. They have found that combination of a selective salt of a dicarboxylic acid viz. disodium fumarate along with a specific extract of a plant source e.g. Salvia officinalis rich in certain organic aromatic acids provides for synergic skin lightening benefits. They have further found that inclusion of certain activity enhancers in the composition of the invention improves the skin lightening efficacy.
U.S. Pat. No. 7,332,152 discloses a cosmetic composition comprising vitamin B6, vitamin B3 and an organic acid that interact synergistically to enhance skin lightening. JP 418017 discloses a sebum secretion promoting agent which is made by selecting one or more compounds selected from citric acid, succinic acid, fumaric acid, malic acid or an ester thereof and an extracted solution of Salvia officinalis L. with ethanol.
JP 2001 163755 discloses a preparation for external use for skin for improved skin bleaching effect, excellent in stability and safety by including at least one plant extract selected from those derived from Morus alba, Scutellaria baicalensis, Rosamarinus officinalis, Matricaria chamomilla, Aloe ferox (or Aloe africane, Aloe spicata, Aloe barbadensis or Aloe arborescens), Hamamelis virginiana, Aesculus hippocastanum, Rosa multiflora or species closely related thereto (Rosaceae), Salvia officinalis, Lamium album, Isodon japonicus (or Isodon trichocarpus), Glycyrrhiza glabra (or Glycyrrhiza uralensis), Saxifraga stolonfera, Rosa centigolia, and/or Pyracantha fortuneana, and an acylated derivative of glycosyl-L-ascorbic acid.
Thus no published information exists that specifically teaches synergistic interaction of disodium fumarate with an extract of plant source like Salvia officinalis to provide enhanced skin lightening benefits.
It is an object of the present invention to provide for a skin lightening composition that exhibits enhanced skin lightening as compared to known products available in the market.
It is another object of the present invention to provide for enhanced skin lightening composition using specific actives extracted from both a natural source and a synthetic source.